Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IIH > L08: Intorduction Of Viruses > Flashcards

L08: Intorduction Of Viruses Flashcards

1
Q

What scheme is used to classify viruses

A

Baltimore scheme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the baltimore scheme classify viruses depending on

A

Rna or dna
Double strand or single strand
Is there a reverse transcriptase
Sense (like mRNA) or antisense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many groups are there in the Baltimore scheme

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is group 1

A

Double stranded DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is group 2

A

Single stranded DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is group 3

A

Double stranded rna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is group 4

A

Sense RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is group 5

A

Antisense RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is group 6

A

RNA reverse transcribing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is group 7

A

DNA reverse transcribing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the viral life cycle

A

1) virus glycoproteins interact with the cells surface receptor
2) this enables receptor mediated endocytoses so virus enters cytoplasm
3) virus capsid with genetic material is transported to the cells nucleus
4) nucleic acids become, transcribed, transplanted, replication.
5) envelopment of genome
5) new protein/virus becomes assembled and released out of the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is it important to know every stage of virus replication

A

So we can target it by drugs against them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are drug target for viruses

A 
Virion uncoating 
DNA polymerase
Reverse transcriptase
Viral protease
Viral neuraminidase
Inositol monophospahte dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the most clinically important viruses

A

Influenza virus
Hepatitis b and c
HIV
Herpes virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the features of influenza

A

Enveloped
With glycoproteins of haemaglutinin and neuraminidase
Single RNA genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 3 types of influenza that infect humans

A

Influenza a: cause pandemic
Influenza b: cause seasonal epidemics
Influenza c: cause mild respiratory illness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is influenza virus divided into subtypes depending on

A

Haemoglutinin or neuraminidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What receptor does the haemagglutinin interact with in the airway epithelium

A

Alpha 2,6 Sialic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why does influenza of haemaglutinin give repeated infections

A

Neutralising antibodies that stop haemooglutinin from binding to alpha 2,6 sialic acid stops working due to antigenic variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 2 types of antigenic variations

A

Antigenic shift

Antigenic drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is an antigenic drift

A

1) Small changes in the genes of influenza that happen continuously
2) the viruses accumulate overtime and generate proteins that have haemolgutinin mutated so neutralising antibodies do not recognise it
3) influenza therefore enters cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why do mutations of virus genes occurs

A

Rna viruses have to replicate its RNA genome by RNA polymerase which lacks proofreading compared to DNA polymerase so they have greater mutations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is antigenic shift

A

This is not about mutation
A cell with 2 different viruses have there virus segments completely swapped
This results in a new virus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How can antigenic shifts occur

A

Virus from birds get into pigs

Human influenza gets into pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What does antigenic shift cause

A

Pandemic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which type influenza has antigenic shift occurs

A

Only in influenza a

27
Q

What are the features of hepatitis b

A

Enveloped
DNA
Glycoproteins
E antigen expressed when the virus is replicating itself

28
Q

How can hep b be transmitted

A 
Perinatal transfusion 
Blood to blood
Needle stick injury 
Sexual 
Medical instruments
29
Q

Is hep b acute or chronic infections

A

Can start as acute but develop into chronic

30
Q

How would you test for hep b

A

Test for antibodies

31
Q

What will you see in an acute hep b infection in a test

A

HBe antigen during first exposure of virus

IgM antibodies after hep b exposure

32
Q

What will you detect in chronic hep b infection

A

DNA

Hep b antigen hbe antigen

33
Q

What is the features of hepatitis c

A

Enveloped
Single stranded RNA
Glycoproteins 1 and 2

34
Q

How is hepatitis c transmitted

A

Blood borne e.g sharing injection equipment

35
Q

Is hepatitis c infection acute or chronic

A

Starts as acute then can become chronic

36
Q

How would you test for hepatitis c

A

Antibody testing to see if you have the infection before

If antibody test is positive you carry out viral nuclei acid test to tell you if you have a current infection

37
Q

What does the test results show if you have had hep c but no current infection

A

Antibody positive

Rna negative

38
Q

What would show if there is an acute infection

A

Antibody postive

Rna postive

39
Q

Why do we get point mutation occuring for hepatitis c

A

Hepatitis c is a RNA virus so rna polymerase does not proofread which leads to point mutations

40
Q

What does treatment to chronic hepatitis c depend on

A

Treatment depepends on genotype of hepatitis b

41
Q

What is the structure of HIV

A

Enveloped
Rna single stranded
Glycoproteins : GP41 and GP120

42
Q

Which immunity cells does HIV infect

A

CD4+ T cells

Macrophages

43
Q

What are the subtypes of HIV

A

HIV-1

HIV-2

44
Q

Does HIV involve acute or chronic infection

A

Chronic infection

45
Q

Why do people with HIV get chronically infected

A

HIV replicated of low levels for decades

Virus loads increase as CD4+ T cell count drops

46
Q

What happens when the person with HIV has a CD4+ T cell count below 200cell per mom

A

Person is diagnosed with AIDS

47
Q

What is the maximal survival with someone with aids

A

3 years

48
Q

Why is the maximum survival really low for AIDS

A

The person does not have immunity so they a prone to infections

49
Q

Which infections are opportunistic in AIDS

A 
Cryptococcal meningitis 
Toxoplasmosis 
Pneumocystis pneumonia 
Oesophageal candidiasis 
Certain cancers
50
Q

How doe we test for HIV in the lab

A

HIV antibody test
If postive for antibody: nucliec acid test (measures virus load)
Antigen/antibody test: measures P24 antigen which is a marker of active virus replication

51
Q

If HIV is an RNA virus what does this mean in terms of mutations

A

It is prone to mutations due to RNA polymerase not proofreading

52
Q

What is the structure of herpes virus

A

Enveloped
Linear double stranded DNA
Glycoproteins
Has proteins inside which activate innate immunity

53
Q

What are the 2 subtypes of herpes virus

A

HSV-1

HSV-2

54
Q

What can HSV-1 cause

A

Stomatitis

55
Q

What is stomatitis

A

Inflammation of mouth and lips

56
Q

Why do you get stomatitis in HSV-1

A

Replication occurs in the mucoepithelial cells

57
Q

What type of infection does herpes present with during later on in life

A

Latent infection

58
Q

How does latency occur in herpes virus

A

Virus turns off its genes so the infected cells become immunologically silent
Reactivation of the virus can occur
Hsv1-/2 invade sensory neurones and establish latency in ganglia

59
Q

If the virus invades the CNS what can this result in

A

Meningitis

60
Q

What does varicella zoster virus cause

A

Chicken pox and shingles

61
Q

Who gets chickenpox

A

Children

62
Q

Who gets shingles

A

Elderly

63
Q

What type of infection is shingles

A

Latent infection

IIH (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions